Well packer

ABSTRACT

The improved well packer disclosed herein includes a tubular body arranged at one end for connection with a running string, a unitary gripping member positioned on the body and movable between a casing engaging position and a retracted position, and an articulated head member located on the tubular body having an upper end engagable with the lower end of the gripping member and also being engagable with the casing. The lower end of the articulated head member is engagable with a movable abutment positioned on the tubular body. The well packer also includes packing means located on the tubular body that is arranged to be deformed into sealing engagement with the casing. The articulated head member engages the unitary gripping member and the casing to transfer a portion of the eccentric load of the gripping member into the casing and thus prevent the imposition of a moment on the tubular body. The lower end of the articulated head engages the abutment member parallel to the axial centerline of the tubular body.

United States Patent 1 Read WELL PACKER Norman Weldon Read, Dallas, Tex.

Filed: Jan. 2, 1973 Appl. No.: 320,221

[52] US. Cl. 166/140, 166/216 [51] Int. Cl. E2lb 23/00 Field of Search 166/119, 134, 138, 216, 166/217, 206, 211, 139, 141, 140

[56] References Cited UNITED STATES PATENTS I 5/1953 Soberg et al 166/211 X 9/1959 Clark 166/140 12/1970 Kilgore 166/139 X Primary ExaminerGeorge H. Krizmanich Attorney, Agent, or Firm R0y L. Van Winkle; Michael J. Caddell June 25, 1974 5 7 ABSTRACT The improved well packer disclosed herein includes a tubular body arranged at one end for connection with a running string, a unitary gripping member positioned on the body and movable between a casing engaging position and a retracted position, and an articulated head member located on the tubular body having an upper end engagable with the lower end of the gripping member and also being engagable with the casing. The lower end of the articulated head member is engagable with a movable abutment positioned on the tubular body. The well packer also includes packing means located on the tubular body that is arranged to be deformed into sealing engagement with the casing. The articulated head member engages the unitary gripping member and the casing to transfer a portion of the eccentric load of the gripping member into the casing and thus prevent the imposition of a moment on the tubular body. The lower end of the articulated head engages the abutment member parallel to the axial centerline of the tubular body.

10 Claims, 3 Drawing Figures WELL PACKER BACKGROUND OF THE INVENTION This invention relates generally to improved packers for use in well bores. More particularly, but not by limitation, this invention relates to an improved packer of the type having a unitary gripping member thereon.

US. Pat. No. 3,548,936, issued Dec. 22, 1970, to M. D. Kilgore, et al, illustrates a number of packer embodiments incorporating unitary gripping members. That patent also clearly discloses the function and operation of the unitary gripping member.

It will be apparent from a review of that patent that the loads imposed on the packer during the setting of the unitary gripping member are eccentric, that is, they are disposed to one side of the axial centerline of the packer. Thus, a moment is imposed on the packer which may cause the packer to move toward one side of the casing rather than remaining concentric therewith. While packers constructed in accordance with the disclosure of the above patent have worked satisfactorily, some difficulties have been encountered due to the eccentricity of the load.

These difficulties have occurred primarily in the larger sizes of packers and in particular when the packer includes only one of the unitary gripping members. It will be appreciated that the larger the diameter of the packer the greater the eccentricity of the load and thus, the greater the moment that is imposed on the packer tending to move it off-center.

It is, therefore, one object of this invention to provide an improved well packer of the unitary gripping member type that remains generally concentrically positioned within the casing during the setting operation.

Another object of the invention is to provide an improved well packer that includes a single unitary gripping member that remains concentric with the casing during the setting operation. I

Still another object of the invention is to provide improved means for use on a well packer that prevents the imposition of a moment on the packer during setting of the unitary gripping member.

SUMMARY OF THE INVENTION This invention provides an improved well packer for use in a casing or the like disposed in a well bore. The improved well packer includes: a tubular body arranged for connection with a running-in string; a unitary gripping member encircling the tubular body and having upper and lower ends, a casing engaging portion located adjacent at each end and on generally opposite sides thereof, and a contact portion on the lower end thereof; an abutment member positioned movably on the tubular body; and, moment preventing means on the tubular body between the gripping member and the abutment member arranged to engage the casing, the abutment member and the gripping member for preventing the imposition of a moment on the packer. The well packer also includes packing means on the tubular body arranged to be deformed into sealing engagement with the casing and with the tubular body.

The foregoing and the additional objects and advantages of the invention will become more apparent when read in conjunction with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a view, partly in elevation and partly in cross-section, illustrating a packer constructed in accordance with the invention.

FIG. 2 is a view of a portion of FIG. 1 showing the components thereof in another operating position.

FIG. 3 is a transverse cross-sectional view of a portion of FIG. 2 taken generally along the line 33-of FIG. 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawing and to FIG. 1 in particular, showntherein and generally designated by the reference character 10 is a well packer constructed in accordance with the invention. The well packer 10 is illustrated as being disposed in a casing 12 that is located in a well bore (not shown).

The well packer 10 includes a tubular body or mandrel 14 that is threadedly connected at its upper end with an adaptor 16 that provides a downwardly facing shoulder. or abutment 18. The adaptor 16 is threadedly connected with a conduit or running-in string 20 that extends to the surface of the well bore. The conduit 20 is utilized for the purpose of moving the well packer 10 through the well bore.

The tubular body 14 and packer 10 has a longitudinal or axial centerline 22 that is coincident with the centerline of the casing 12 when the packer 10 is concentrically disposed therein. The tubular body 14 includes a portion 24 of reduced diameter forming a downwardlyfacing, exterior flange 26 for purposes that will be explained hereinafter. It will be noted that the reduced diameter portion 24 extends through a flange or abutment' member 27 which is slidinglypositioned thereon.

The abutment member 27 provides an upwardly facing surface 28 and a downwardly facing surface 30 that is in engagement with deformable packing 32. The lower end of the packing 32 is in engagement with an abutment 34 that is attached to the tubular body 14 by one or more shear screws 35. It will be appreciated that movement of the abutment member 27 and the abutment 34 relatively together will deform the packing 32 into sealing engagement with the casing 12 and with the tubular body 14 in a manner well known in the well packer art.

Encircling the tubular body 14, just below the downwardly facing shoulder 18, is a gripping member 36 that is arranged for both sliding and pivoting movement with respect to the tubular body 14. To provide such movement, the exterior of the tubular body 14 is provided with a pair of diametrically opposed slots 38 and 40 (see FIG. 3). Pivot means 42 carried by the gripping member 36 are located in the slots 38 and 40 and will be described in more detail hereinafter.

The gripping member 36 illustrated includes an upper end 44 and a lower end 46 that are angularly disposed with respect to each other. The upper end 44 includes a contact portion 48 that is offset from the pivot axis of the gripping member 36 in a direction to cause the gripping member 36 to rotate toward the retracted position illustrated in FIG. 1 when in engagement with the downwardly facing shoulder 18.

The lower end 46 on the gripping member 36 includes a contact portion 50 that is offset from the pivot axis of the gripping member 36 in the same direction as was contact portion 48. It can be seen that engagement of the contact portion 50 will cause the gripping member 36 to pivot toward the casing engaging position illustrated in FIG. 2.

The gripping member 36 also includes an upper gripping portion 52 and a lower gripping portion 54 disposed adjacent the upper and lower ends 44 and 46 respectively. The gripping portions 52 and 54 are preferably provided with teeth to enhance their frictional engagement with the casing 12.

The gripping member 36 is relieved from the bottom end 46, providing a downwardly facing shoulder 56 thereon. Similarly, the gripping member 36 is relieved from the upper end 44 providing an opening 58 through which a leaf-type spring 60 extends. The spring 60 has one end that is attached to the gripping member 36 and the other end frictionally engaging the tubular body 14 resiliently urging the gripping member 36 toward the retracted position shown in FIG. 1.

Encircling the tubular body 14 between the gripping member 36 and the movable abutment member 27 is an articulated head 62. The articulated head 62 includes a top end 64 and a bottom end 66. The top end 64 includes a contact portion 68 that is engageable with the contact portion 50 on the lower end 46 of the gripping member 36. The bottom end 66 of the head 62 includes an arcuate contact portion 70 configured in such a manner that the contact portion 70 engages the movable abutment member 27 along a line extending through and disposed normally to the centerline 22. Arcuate contact portion 70 is formed by a cylindrical surface normal to the plane of the figure intersecting tubular member 62 which results in two downwardly projecting, opposed arcuate surfaces. Since the crosssectional view of FIG. 2 is taken along a cross-sectional plane between these two surfaces, only one surface (70) is visible in the figure.

The head 62 also includes an upper casing engaging portion 72 located adjacent to the top contact portion 68 and a lower casing engaging portion 74 located adjacent to the bottom end 66 and on the relatively opposite side of the head 62 from the contact portion 72. The head 62 has been counterbored from the top end 64 providing an upwardly facing shoulder 76, which when in the retracted position, is in engagement with the downwardly facing flange 26 on the tubular body 14 to aide in the retaining the head 62 in the retracted position shown in FIG. 1 as the well packer is lowered into the well bore.

A slot 78 extends from the top end 64 of the head 62 and is sized to receive a lug 80 which is welded to or otherwise secured to the tubular body 14. The lug 80, in cooperation with the slot 78, aides in maintaining the head 62 in alignment with the gripping member 36 so that the contact portions 50 and 68 will be in the proper position for engagement during the operation of the well packer 10. The lug 80 also functions during the retrieval of the well packer 10 to engage the downwardly facing shoulder 56 in the gripping member 36 to move the gripping member 36 from the set or casing engaging position to the retracted position It is necessary in the operation of the well packer 10 to provide some means for affording relative movement between various parts of the packer 10. The transverse cross-section of FIG. 3 illustrates the structure of drag springs 82, which are directly mounted on the gripping member 36 and are resiliently biased into frictional engagement with the casing 12.

As can be seen therein, the pivot means 42 includes a pair of pivot bushings or members 84 that extend through the wall of the gripping member 36 and project into the slots 38 and 40 formed in the tubular body 14. The bushings 84 are each counterbored to receive a coil spring 86 which encircles stem 88 of pins 90. Each of the pins 90 has an enlarged head 92 that engages one end of the springs 86 while the other end of the springs 86 is in engagement with the bushings 84. The arrangement is such that the springs 86 bias the pins 90 outwardly against the interior of the drag springs 82. If the drag springs 82 have sufficient spring characteristics and will afford a sufficient life for the operation of the well packer 10, the pins 90 and springs 86 can be omitted.

It should be pointed out that the provision of the drag springs 82 directly on the gripping member 36 is an arrangement not heretofore known and affords the advantage of being able to omit a separate drag spring or drag block assembly and, thus, shorten the overall length of the well packer as well as considerably decreasing the cost.

OPERATION OF THE PREFERRED EMBODIMENT With the conduit 20 connected to the packer 10, the packer 10 is lowered into the casing 12 until the packer 10 reaches the desired location in the well bore. As the packer 10 moves downwardly, the drag springs 82 are in frictional engagement with the casing 12 so that the gripping member 36 rides upwardly in the slots 38 and 40 engaging the upper end 44 of the gripping member 36 in with the shoulder 18. Such engagement, plus the action of the spring 60, retains the gripping member 36 in the retracted position.

lt should also be noted that the upwardly facing annular shoulder 76 on the articulated head 62 will remain in engagement with the downwardly facing shoulder 26 on the tubular body 14. With the shoulders 26 and 76 in engagement, the articulated head 62 remains in the retracted position illustrated in H0. 1.

After the packer 10 has reached the desired position in the casing 12, the conduit 20 is raised pulling the tubular body 14 upwardly therewith. Due to the frictional engagement of the drag springs 82 with the casing 12, the gripping member 36 remains in a relatively fixed position. The upward movement of the tubular body 14 carries the lower abutment 34 upwardly, raising the packer 32, the movable abutment member 27, and the articulated head 62 therewith toward the relatively fixed gripping member 36.

Continued upward movement of the tubular body 14 brings the contact portion 68 on the upper end 64 of the head 62 into engagement with the contact portion 50 on the lower end 46 of the gripping member 36. When this occurs, the gripping member 36 is pivoted about the pivot means 42 until the casing engaging portions 52 and 54 thereon frictionally engage the casing 12 locking the gripping member 36 in the casing 12.

Simultaneously, the articulated head 62 rotates or pivots on the tubular body 14 until the casing engaging portions 72 and 74 thereon are in engagement with the casing 12 as illustrated in FIG. 2. The lower contact portion of the articulated head 62 is in engagement with the movable abutment member 27 along a line that extends through and normal to the axial centerline 22 of the tubular body 14.

From the foregoing, it can beseen that the gripping member 36 due to the location of the casing engaging portions 52 and 54 thereon and the offset location of the contact portion 68 on the lower end 46 will normally have a tendency to exert an eccentric load on anything engaging the contact portion 68. To compensate for this, the articulated head 62 is pivoted in an opposite direction to the pivotal direction of the gripping member 36 and engages the casing through casing engaging portions 72 and 74 to transfer the lateral component of the eccentric loading force into the casing 12 thereby counteracting any moment that the gripping member 36 may impose. Further, the arrangement of the contact portion 70 on the head 62 prevents the imposition of any, other than a load parallel to the centerline 22 from being imposed upon the movable abutment member 27. Thus, the packer will remain substantially concentric with the casing 12 during the imposition of setting forces on the packer 10.

After the gripping member 36 has been set, additional upward movement of the tubular body 14 moves the fixed abutment 34 relatively toward the movable abutment member 27 deforming the packing 32 therebetween. The packing 32, under the force imposed by the fixed abutment 34, deforms into fluid-tight sealing engagement with the tubular body 14 and with the casing 12.

To remove the packer 10 from the well bore, additional upward force is imposed upon the conduit and tubular body 14 until the shear screws 35 part permitting the tubular body 14 to move upwardly relative to the gripping member 36. The upward movement of the tubular body 14 continues until the lug 80 thereon engages the downwardly facing shoulder 36 on the gripping member 56. This engagement forces the gripping member 36 to rotate from the set position illustrated in FIG. 2 to the retracted position illustrated in FIG. 1.

After the gripping member 36 has been released, the head 62 is returned in its retracted position and the movable abutment member 27 moves relative to the fixed abutment 34 permitting the packing 32 to return to its undeformed condition. After the foregoing has occurred, it is only necessary to continue raising the conduit 20 to remove the well packer 10 from the well bore.

From the foregoing, it should be apparent that a well packer constructed in accordance with this invention includes a unitary gripping member and means associated therewith that prevents the imposition of a moment on the packer which would otherwise tend to move the packer out of concentricity with the casing and thus interfere with the settingof the packer in the well.

Not only does a packer constructed in accordance with this invention avoid the nonconcentric location of the packer, but it also avoids the imposition of eccentric loads on moving parts of the packer which could and, have in the past, occasionally resulted'in the jamming of the moving parts.

It will be understood that the embodiment described in detail hereinbefore is presented by way of example only and that many changes and modifications can be made thereto without departing from the spirit and scope of the invention.

. '6 The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

l. A well packer arranged for movement through a casing or the like disposed in a well bore, said packer comprising:

an elongated tubular body arranged for connection with means for moving the packer through the easing and having a longitudinal centerline; a gripping member encircling said body and moveable between a holding position wherein said gripping member engages the casing and a retracted position wherein said gripping member is out of engagement with said casing, said gripping member including a unitary body member having first and second ends,

first and second wall engaging portions adjacent said first and second ends, respectively, and located on relatively opposite sides of said member, and

a contact portion on said second end offset from said centerline toward said second wall engaging v portion;

an abutment member moveably located on said body;

moment preventing means positioned on said body between said abutment member and gripping member, said means engaging said gripping member contact portion to move said gripping member into said holding position, engaging said abutment member along a contact line, extending generally through and, normal to said centerline, and engaging said casing for preventing the imposition of a moment on said tubular body; and,

packing means encircling said tubular body adjacent to said abutment member for forming a seal with the casing and said tubular body.

2. The well packer of claim 1 wherein said moment preventing means includes a unitary head member having:

a top and a bottom end;

top and bottom casing engaging portions adjacent said top and bottom ends, respectively;

a top contact portion on said top end offset from said centerline toward said top casing engaging portion and engageable with the contact portion on said gripping member; and,

a bottom contact portion on said bottom end engageable with said abutment member.

3. The well packer of claim 2 wherein said bottom end comprises a pair of opposed, arcuate bottom contact portions engaging said abutment member at two places defined by said contact line.

4. The well packer of claim 1 and also including alignment means for retaining said gripping member and said moment preventing means in relative positions on said tubular body wherein said gripping member and moment preventing means are both in engagement with the casing.

5. The well packer of claim 2 and also including alignment meansfor retaining said head member and gripping member in positions wherein said gripping member contact portion engages the top contact portion on said head member.

6. The well packer of claim 5 wherein said alignment means includes:

7 pivot means operably disposed between said gripping member and tubular body for permitting relative pivotal and longitudinal sliding movement therebetween while preventing relative rotation therebetween about said longitudinal centerline; and, means carried by said tubular body for engaging said head member to prevent relative rotation between said tubular body and head member about said longitudinal centerline. 7. A well packer arranged for movement through a casing or the like disposed in a well bore, said packer comprising:

an elongated tubular body arranged for connection with means for moving the packer through the casing and having an axial centerline;

a gripping member encircling said body and moveable between a holding position wherein said gripping member engages the casing and a retracted position wherein said gripping member is out of engagement with said casing, said gripping member including a unitary body member having first and second ends, a first and a second wall engaging portion adjacent said first and second ends, respectively, and located on relatively opposite sides of said member and a contact portion on said second end offset from said centerline toward said second wall engaging portion;

a first abutment member moveably located on said body;

a head member encircling said'body between said first abutment member and gripping member, said head member being moveable between a casing engaging position and a retracted position out of engagement with the casing, said head member having a top and a bottom end,

top and bottom casing engaging portions adjacent said top and bottom ends, respectively,

a top contact portion offset from said centerline toward said top casing engaging portion and engagable with the contact portion on said gripping member, and

a bottom contact portion engagable with said first abutment member along a contact line extending generally through and normal to said centerline;

a second abutment member mounted on said body;

and,

packing means encircling said body between said first and second abutment members arranged to be deformed into sealing engagement with said body and casing upon movement of said first and second abutment members toward each other.

8. The well packer of claim 7 and also including alignment means for retaining said head member and gripping member in positions wherein the contact portion on the second end of said gripping member engages the top contact portion of said head member.

9. The well packer of claim 8 wherein said alignment meansincludes:

pivot means operably disposed between said gripping member and tubular body for permitting relative pivotal and longitudinal sliding movement therebetween while preventing relative rotation therebetween about said longitudinal centerline; and,

-means carried by said tubular body for engaging said head member to prevent relative rotation between said tubular body and head member about said longitudinal centerline.

10. The packer of claim 9 wherein said bottom end isbifurcated providing a pair of spaced bottom contact portions located on relatively opposite sides of said tubular body and engaging said first abutment member at two places defined by said contact line. 

1. A well packer arranged for movement through a casing or the like disposed in a well bore, said packer comprising: an elongated tubular body arranged for connection with means for moving the packer through the casing and having a longitudinal centerline; a gripping member encircling said body and moveable between a holding position wherein said gripping member engages the casing and a retracted position wherein said gripping member is out of engagement with said casing, said gripping member including a unitary body member having first and second ends, first and second wall engaging portions adjacent said first and second ends, respectively, and located on relatively opposite sides of said member, and a contact portion on said second end offset from said centerline toward said second wall engaging portion; an abutment member moveably located on said body; moment preventing means positioned on said body between said abutment member and gripping member, said means engaging said gripping member contact portion to move said gripping member into said holding position, engaging said abutment member along a contact line extending generally through and, normal to said centerline, and engaging said casing for preventing the imposition of a moment on said tubular body; and, packing means encircling said tubular body adjacent to said abutment member for forming a seal with the casing and said tubular body.
 2. The well packer of claim 1 wherein said moment preventing means includes a unitary head member having: a top and a bottom end; top and bottom casing engaging portions adjacent said top and bottom ends, respectively; a top contact portion on said top end offset from said centerline toward said top casing engaging portion and engageable with the contact portion on said gripping member; and, a bottom contact portion on said bottom end engageable with said abutment member.
 3. The well packer of claim 2 wherein said bottOm end comprises a pair of opposed, arcuate bottom contact portions engaging said abutment member at two places defined by said contact line.
 4. The well packer of claim 1 and also including alignment means for retaining said gripping member and said moment preventing means in relative positions on said tubular body wherein said gripping member and moment preventing means are both in engagement with the casing.
 5. The well packer of claim 2 and also including alignment means for retaining said head member and gripping member in positions wherein said gripping member contact portion engages the top contact portion on said head member.
 6. The well packer of claim 5 wherein said alignment means includes: pivot means operably disposed between said gripping member and tubular body for permitting relative pivotal and longitudinal sliding movement therebetween while preventing relative rotation therebetween about said longitudinal centerline; and, means carried by said tubular body for engaging said head member to prevent relative rotation between said tubular body and head member about said longitudinal centerline.
 7. A well packer arranged for movement through a casing or the like disposed in a well bore, said packer comprising: an elongated tubular body arranged for connection with means for moving the packer through the casing and having an axial centerline; a gripping member encircling said body and moveable between a holding position wherein said gripping member engages the casing and a retracted position wherein said gripping member is out of engagement with said casing, said gripping member including a unitary body member having first and second ends, a first and a second wall engaging portion adjacent said first and second ends, respectively, and located on relatively opposite sides of said member and a contact portion on said second end offset from said centerline toward said second wall engaging portion; a first abutment member moveably located on said body; a head member encircling said body between said first abutment member and gripping member, said head member being moveable between a casing engaging position and a retracted position out of engagement with the casing, said head member having a top and a bottom end, top and bottom casing engaging portions adjacent said top and bottom ends, respectively, a top contact portion offset from said centerline toward said top casing engaging portion and engagable with the contact portion on said gripping member, and a bottom contact portion engagable with said first abutment member along a contact line extending generally through and normal to said centerline; a second abutment member mounted on said body; and, packing means encircling said body between said first and second abutment members arranged to be deformed into sealing engagement with said body and casing upon movement of said first and second abutment members toward each other.
 8. The well packer of claim 7 and also including alignment means for retaining said head member and gripping member in positions wherein the contact portion on the second end of said gripping member engages the top contact portion of said head member.
 9. The well packer of claim 8 wherein said alignment means includes: pivot means operably disposed between said gripping member and tubular body for permitting relative pivotal and longitudinal sliding movement therebetween while preventing relative rotation therebetween about said longitudinal centerline; and, means carried by said tubular body for engaging said head member to prevent relative rotation between said tubular body and head member about said longitudinal centerline.
 10. The packer of claim 9 wherein said bottom end is bifurcated providing a pair of spaced bottom contact portions located on relatively opposite sides of said tubular body and engaging said first abutment member at two places defined by said contact line. 